Combined actions of multiple hairpin loop structures and sites of rate-limiting endonucleolytic cleavage determine differential degradation rates of individual segments within polycistronic puf operon mRNA. 1990

G Klug, and S N Cohen
Department of Genetics, Stanford University School of Medicine, California 94305-5120.

Differential expression of the genes within the puf operon of Rhodobacter capsulatus is accomplished in part by differences in the rate of degradation of different segments of the puf transcript. We report here that decay of puf mRNA sequences specifying the light-harvesting I (LHI) and reaction center (RC) photosynthetic membrane peptides is initiated endoribonucleolytically within a discrete 1.4-kilobase segment of the RC-coding region. Deletion of this segment increased the half-life of the RC-coding region from 8 to 20 min while not affecting decay of LHI-coding sequences upstream from an intercistronic hairpin loop structure shown previously to impede 3'-to-5' degradation. Prolongation of RC segment half-life was dependent on the presence of other hairpin structures 3' to the RC region. Inserting the endonuclease-sensitive sites into the LHI-coding segment markedly accelerated its degradation. Our results suggest that differential degradation of the RC- and LHI-coding segments of puf mRNA is accomplished at least in part by the combined actions of RC region-specific endonuclease(s), one or more exonucleases, and several strategically located exonuclease-impeding hairpins.

UI MeSH Term Description Entries
D008969 Molecular Sequence Data Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories. Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009876 Operon In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION. Operons
D010957 Plasmids Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS. Episomes,Episome,Plasmid
D002872 Chromosome Deletion Actual loss of portion of a chromosome. Monosomy, Partial,Partial Monosomy,Deletion, Chromosome,Deletions, Chromosome,Monosomies, Partial,Partial Monosomies
D005798 Genes, Bacterial The functional hereditary units of BACTERIA. Bacterial Gene,Bacterial Genes,Gene, Bacterial
D001483 Base Sequence The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence. DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012241 Rhodopseudomonas A genus of gram-negative, rod-shaped, phototrophic bacteria found in aquatic environments. Internal photosynthetic membranes are present as lamellae underlying the cytoplasmic membrane.
D012333 RNA, Messenger RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. Messenger RNA,Messenger RNA, Polyadenylated,Poly(A) Tail,Poly(A)+ RNA,Poly(A)+ mRNA,RNA, Messenger, Polyadenylated,RNA, Polyadenylated,mRNA,mRNA, Non-Polyadenylated,mRNA, Polyadenylated,Non-Polyadenylated mRNA,Poly(A) RNA,Polyadenylated mRNA,Non Polyadenylated mRNA,Polyadenylated Messenger RNA,Polyadenylated RNA,RNA, Polyadenylated Messenger,mRNA, Non Polyadenylated
D015152 Blotting, Northern Detection of RNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES. Northern Blotting,Blot, Northern,Northern Blot,Blots, Northern,Blottings, Northern,Northern Blots,Northern Blottings
D015183 Restriction Mapping Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA. Endonuclease Mapping, Restriction,Enzyme Mapping, Restriction,Site Mapping, Restriction,Analysis, Restriction Enzyme,Enzyme Analysis, Restriction,Restriction Enzyme Analysis,Analyses, Restriction Enzyme,Endonuclease Mappings, Restriction,Enzyme Analyses, Restriction,Enzyme Mappings, Restriction,Mapping, Restriction,Mapping, Restriction Endonuclease,Mapping, Restriction Enzyme,Mapping, Restriction Site,Mappings, Restriction,Mappings, Restriction Endonuclease,Mappings, Restriction Enzyme,Mappings, Restriction Site,Restriction Endonuclease Mapping,Restriction Endonuclease Mappings,Restriction Enzyme Analyses,Restriction Enzyme Mapping,Restriction Enzyme Mappings,Restriction Mappings,Restriction Site Mapping,Restriction Site Mappings,Site Mappings, Restriction

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